ductless gland vs secreter

ductless gland and secreter both are nouns.

Word	Noun	Adjective	Verb	Adverb
ductless gland	Yes	No	No	No
secreter	Yes	No	No	No

As nouns, secreter is a hypernym of ductless gland; that is, secreter is a word with a broader meaning than ductless gland:

ductless gland: any of the glands of the endocrine system that secrete hormones directly into the bloodstream
secreter: any of various organs that synthesize substances needed by the body and release it through ducts or directly into the bloodstream

Other hypernyms of ductless gland include gland, secretor, secretory organ.

ductless gland (noun)	secreter (noun)
any of the glands of the endocrine system that secrete hormones directly into the bloodstream	any of various organs that synthesize substances needed by the body and release it through ducts or directly into the bloodstream